The recapping or retreading of both automobile and truck tires is a large industry. The process includes the application of a precured tread material to a tire casing that has been inspected and buffed to receive the tread. The tread is cemented to the tire casing and the casing is mounted on a curing rim. The cement is then cured under high temperature and pressure in a pressure chamber, typically by steam and compressed air. However, to achieve proper curing the bonding surfaces between the tire casing and tread must not be exposed to the steam. Typically, a flexible envelope is provided which covers the bonding surfaces and is sealed to either the tire casing or curing rim to isolate the bonding surfaces from the steam in the chamber.
One method for enclosing a tire casing and tread material by an airtight flexible cover is disclosed and claimed in U.S. Pat. No. 3,236,709 issued Feb. 22, 1966 to Carver. In the method of this patent, the flexible cover includes a pair of flexible sidewall members which extend over the tire beads so as to engage the same, covering the sidewalls of the tire. A rim is provided which has peripheral flanges. The cover walls extend intermediate the beads and the rim flanges to be in sealing engagement therebetween.